1. Field of the Invention
The present invention is broadly concerned with improved chamber-type vacuum packaging machines and conveyor assemblies adapted for use with such machines and in a variety of other contexts as well. More particularly, the invention pertains to conveyor assemblies each including a continuous shiftable conveyor belt adapted to extend along the length of a chamber or other type of machine operating table and having an upper and a lower run; a belt supporting and shifting assembly is provided for supporting the belt with both the upper and lower runs being located atop the machine table and is operable for shifting of the belt so that the upper run thereof may be selectively moved into and out of the package sealing station of the table. In other aspects, the invention relates to double chamber packaging equipment having a continuous conveyor system.
2. Description of the Prior Art
Chamber-type vacuum packaging machines have long been used in the packaging industry, particularly in connection with the packaging of food products or medical items. Broadly speaking, such machines include a table presenting a package sealing station, together with a chamber lid shiftable between an open position spaced from the table and a closed, package-sealing position adjacent the sealing station of the table. The machines also have a vacuumization assembly for drawing a package-evacuating vacuum within the lid in the closed position thereof, as well as a sealing device for selectively sealing the evacuated package.
Chamber machines of this character can be simple cabinet units or have an elongated work table allowing loading of packages adjacent one end of the table and subsequent movement of the loaded packages along the table to a sealing station. A further variation is the provision of so-called double chamber machines having an elongated work table with a pair of sealing stations and a single chamber lid alternately movable between the respective sealing stations. A highly successful machine of this type is commercialized by Koch Equipment LLC of Kansas City, Mo. under the trademark Ultravac(copyright) 3000.
Elongated work table single chamber machines of the type described above are typically not provided with conveyor assemblies and no known double-chamber machines include continuous conveyor systems. This is because the expense of providing a conveyor with associated drives and the like would very significantly increase the machine cost. However, it is generally recognized that the machine throughput could be materially enhanced if a low-cost conveyor system could be devised, and particularly one which could be readily retrofitted to existing chamber machines.
The present invention overcomes the problems outlined above and provides improved chamber-type packaging and other equipment having a simplified and relatively low cost conveyor assembly which can be retrofitted to existing equipment or form a part of new units. The conveyor assemblies give enhanced machine operation and throughput, while nevertheless permitting ready belt removal for cleanup purposes.
Broadly speaking, the conveyor assemblies of the invention are adapted inter alia for use with chamber-type vacuum packaging machines having an elongated operating table presenting a package sealing station and a shiftable chamber lid. The conveyor assemblies each have a continuous shiftable conveyor belt of a length to extend along the length of the operating table and present an upper and a lower run. A belt supporting and shifting assembly is also provided which is adapted for coupling to the machine table in order to support the belt with both the upper and lower runs thereof located atop the table; moreover, apparatus is provided for selective shifting of the belt so that the upper run thereof may be moved into and out of the package sealing station. By orienting the conveyor belt with the upper and lower runs thereof atop the table, the entire conveyor assembly can be readily attached to an existing packaging machine without the need for extensive modifications thereof. In like manner, this belt orientation facilitates belt removal for cleanup purposes or belt replacement.
In preferred forms, the belt supporting and shifting assembly comprises a pair of roller units respectively adapted for coupling to the machine table adjacent opposite ends thereof. Each of the roller units includes at least one rotatable roller with the conveyor belt being trained about each such rotatable roller. Preferably, one of the roller units includes a driven a roll to effect the desired shifting of the conveyor belt. A roller unit drive is also provided which is separate from the normal packaging machine drive, which again simplifies the overall system by eliminating any requirement for coupling the conveyor system with the machine drive. In order to facilitate belt removal at least of the roller units (and preferably both) include a roller support movable between a first belt-supporting position and a second belt-releasing position. To this end, it is preferred that the roller units each include a selectively releasable clamp for maintaining the roller unit in the first belt-supporting position thereof, with the clamp being releasable so as to permit movement of the associated roller unit to the second belt-releasing position thereof.
In order to assure smooth belt movement optional first and second slide plate assemblies may be provided. That is, it has been found that a first plate assembly situated directly atop the machine table below the lower belt run, and a second plate assembly located between the upper and lower belt runs, prevent belt hangup and undue drag. Preferably, the plate assemblies are made up of multiple plates which can be readily manipulated, with each of the plates being retained in position by means of upstanding table-mounted pins received within apertures provided in the plates. In one preferred embodiment, each plate assembly is made up of four individual metallic plates presenting undulating upper low-friction belt-engaging surfaces.
The conveyor assemblies of the invention can be used to good effect with single or double chamber machines, i.e., machines having both one and two sealing stations. In either case, the provision of a simplified conveyor assembly in accordance with the invention is a decided operational advantage. More broadly, the conveyor assemblies may be used with virtually any type of elongated, bed-type processing or handling machine or equipment.